msem-instigator

When Evolving Elemental enters, scry 3, then reveal the top card of your library. Put a number of +1/+1 counters on Evolving Elemental equal to that card's mana value.

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Enchant creature
Enchanted creature gets +2/+2.
Whenever enchanted creature attacks, create a 2/2 white Knight creature token that's tapped and attacking.

Sacrifice a creature: You lose life equal to the sacrificed creature's power and draw cards equal to its toughness.

{2}, {T}: Reveal the bottom card of your library. You gain life equal to its mana value. You may put it into your graveyard.

First strike
When Excavator of the Beyond enters, rediscover an artifact card. (Look at the top card of your library. You may reveal it and put it into your hand if it's an artifact card. Otherwise, put it back or into your graveyard.)

Harmony — Exciting Band deals 3 damage to any target.
When Exciting Band enters, harmonize. (Trigger up to one harmony of one permanent you control.)

Vigilance
{G}, {T}: Exile up to three target cards from graveyards. If two or more of those cards share a card type, create a 1/1 colorless Servo artifact creature token.

Gain control of target creature until end of turn. Untap that creature. Until end of turn, it gains haste and “Whenever this creature deals combat damage to a player, aetherize it.” (To aetherize, create a token that's a copy of it, then exile that token.)

Whenever you cast a spell, put a lore counter on Exhilarating Prescience.
At the beginning of your upkeep, exile the top X cards of your library, where X is the number of lore counters on Exhilarating Prescience. You may play those cards until your next turn.

As Exodus of the Khalizors enters, choose Rehison or Danuri.
• Rehison — Whenever an Elf you control enters, you may move a counter from target creature onto another target creature.
• Danuri — Soldiers you control have trample.

Madness {4}{G}{G} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)
Look at the top eight cards of your library. You may reveal a creature card from among them and put it into your hand, then put the rest on the bottom of your library in a random order. Then if this spell was cast for its madness cost, you may put a creature card from your hand onto the battlefield.

{T}: Add {C}.
{1}, {T}, Exile Exotic Isle: Search target opponent's library for a land card and put it onto the battlefield tapped under your control, then that player shuffles. Activate only as a sorcery.

Equipped creature gets +1/+0 and has menace.
Equip {1}

Until end of turn, whenever you cast an instant or sorcery spell, you may discard a card. If you do, draw a card.

Creatures you control get +2/+0 until end of turn. Scouts you control gain trample until end of turn.

Whenever you play a land, you may put a land card from your hand onto the battlefield tapped.

Target creature gains haste until end of turn.
Draw a card.

Other Elves you control get +1/+1.
Whenever another Scout you control deals combat damage to a player, you may reveal the top card of your library. If it's a land card, put it onto the battlefield tapped.

{2}, {T}, Sacrifice Expedition Map: Search your library for a land card, reveal it, put it into your hand, then shuffle.

When Expedition Outfitter enters, create a 1/1 colorless Servo artifact creature token.
At the beginning of each end step, if an artifact was put into your graveyard from the battlefield this turn, Expedition Outfitter deals 1 damage to each opponent.

When Expedition Post enters, create a 1/1 Scout creature token that's all colors.
Creature tokens you control are every creature type.
{4}, {T}: Create a 1/1 Scout creature token that's all colors.

Cycling {3} ({3}, Discard this card: Draw a card.)

When Expensive Tutor enters, tap target land. It doesn't untap during its controller's next untap step.

Equipped creature gets +2/+2 and has double strike and trample.
Equip {5}